Validity of the MISTELS Simulator for Laparoscopy Training in Urology

Abstract

The McGill Inanimate System for Training and Evaluation of Laparoscopic Skills (MISTELS) consists of a series of five laparoscopic exercises performed in an endotrainer box. MISTELS has been validated for use in both training and evaluation of general surgery residents in fundamental laparoscopic skills. The purpose of this study was to demonstrate the construct validity of MISTELS for urology residents. Seventeen participants were evaluated during performance of the five MISTELS tasks (peg transfer, pattern cutting, ligating loop, and suturing with extracorporeal and intracorporeal knots) using the standardized scoring system, which rewards both speed and precision. Participants included 13 urology residents (PGY 1-5), 1 fellow, and 3 urologists experienced in laparoscopy. Results are expressed as median (range). The Mann-Whitney U-test was used to compare MISTELS scores for 9 novice (PGY 1-4) and 8 experienced urologists (PGY 5-attending). P < 0.05 was considered statistically significant. The median MISTELS total normalized score for novices was 52.3 (range 15-68.9) compared with 71.7 (range 56.3-82.9) for experienced urologists (P = 0.007). Although the experienced group achieved higher scores in all five individual tasks, statistically significant differences were demonstrated for the peg transfer and intracorporeal suture tasks only. These data provide evidence for construct validity of the MISTELS system for urology residents.